Transfer data to client before gui opens

[Xaser]

Pretty straight forward question: I want to open a GUI for the player (from the server side using .openGui), however this GUI needs some data to work properly. I prepared a custom packet to send this data, and on the server side code request it to be send before calling .openGui but apparently it doesn't arrive in time and the Gui throws a NullPointerException.

 

So what should I do? My current ideas are: ack the data before having the server call openGui or have the gui wait clientside for the data.

[Xaser]

Yes it does have a container attached, it references 3 inventories (player inventory + 2 temporary ones) as well as two ints and a reference to the other player (only the name is required really). I know that I have to keep the two int values synced myself later (haven't looked into that yet) however the gui also displays the name of another player (hence the gui requires the name or the entity id).,

Edited March 1, 2017 by Xaser

[Xaser]

Spot on, as always, thanks!